this.coffee = false;

function Employee1(coffee) {
    this.coffee = coffee;

    const enterOffice = () => {
      if(this.coffee) {
        console.log('good morning!');
      } else {
        console.log('this sucks');
      }
    }

    return {
      enterOffice: enterOffice
    }
}

const heather1 = new Employee1(true);

heather1.enterOffice(); // good morning!